in Context the SCotian Shelf - COINAtlantic

A recent National Science Advisory Report (DFO
2010a) summarizes major changes in the status
and trends of Canadian marine ecosystems. A
significant change in the Scotian Shelf ecosystem
was a community shift from a large bodied
groundfish dominated system to a pelagic and
invertebrate dominated system. There has also
been a decline in the size and condition of a
number of groundfish species. More information
is provided in Canadian Marine Ecosystem Status
and Trends Report (DFO 2010a) and The Ecosystem
Status and Trends Report for the Gulf of
Maine and Scotian Shelf (Worcester and Parker
2010). The current status and trends of marine
species and communities will be discussed in the
theme papers: Fish Stock Status and Commercial
Fisheries, and Marine Habitats and Communities.
Pelagic Organisms
Pelagic fish of the Scotian Shelf include highly
migratory species such as tuna, swordfish and
sharks (Breeze et al. 2002). Pelagic organisms live
in the water column and at the surface. There are
19 species of sharks that occur in Atlantic Canada.
Five species are considered common residents of
the Scotian Shelf: the blue shark, porbeagle, shortfin
mako, basking shark and the spiny dogfish (Zwanenburg
et al. 2006). Smaller pelagic species include
capelin and herring. Although less is known about
species that live in the mesopelagic or deeper water
of the slope and abyssal plain, over 200 species have
been identified in water depths ranging from 1 000
to 4 000 m. Of these Mycophids (lanternfish) are
the dominant family making up about 30% of the
species composition (Themelis 1996).
http://coinatlantic.ca/index.php/state-of-the-scotian-shelf
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